[apparmor] [PATCH 19/31] parser: Get rid of snprintf_buffer()

[Tyler Hicks]

snprintf_buffer() needed to be modified in order to properly return error
conditions up the stack, instead of exiting, but it's added complexity
didn't seem worth keeping it around.

This patch gets rid of that helper function and adds proper error
handling around the new calls to snprintf().

Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
---
 parser/features.c | 45 +++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/parser/features.c b/parser/features.c
index 1464ac5..5f43c44 100644
--- a/parser/features.c
+++ b/parser/features.c
@@ -42,24 +42,6 @@ struct aa_features {
 	char string[STRING_SIZE];
 };
 
-static char *snprintf_buffer(char *buf, char *pos, ssize_t size,
-			     const char *fmt, ...)
-{
-	va_list args;
-	int i, remaining = size - (pos - buf);
-
-	va_start(args, fmt);
-	i = vsnprintf(pos, remaining, fmt, args);
-	va_end(args);
-
-	if (i >= size) {
-		PERROR(_("Feature buffer full."));
-		exit(1);
-	}
-
-	return pos + i;
-}
-
 struct features_struct {
 	char *buffer;
 	int size;
@@ -70,22 +52,32 @@ static int features_dir_cb(DIR *dir, const char *name, struct stat *st,
 			   void *data)
 {
 	struct features_struct *fst = (struct features_struct *) data;
+	int remaining, len;
 
 	/* skip dot files and files with no name */
 	if (*name == '.' || !strlen(name))
 		return 0;
 
-	fst->pos = snprintf_buffer(fst->buffer, fst->pos, fst->size, "%s {", name);
+	remaining = fst->size - (fst->pos - fst->buffer);
+	len = snprintf(fst->pos, remaining, "%s {", name);
+	if (len == -1) {
+		errno = EIO;
+		return -1;
+	} else if (len >= remaining) {
+		errno = ENOBUFS;
+		return -1;
+	} else
+		fst->pos += len;
 
 	if (S_ISREG(st->st_mode)) {
 		autoclose int file = -1;
-		int len;
-		int remaining = fst->size - (fst->pos - fst->buffer);
+
 		if (!(file = openat(dirfd(dir), name, O_RDONLY))) {
 			PDEBUG("Could not open '%s'", name);
 			return -1;
 		}
 		PDEBUG("Opened features \"%s\"\n", name);
+		remaining = fst->size - (fst->pos - fst->buffer);
 		if (st->st_size > remaining) {
 			PDEBUG("Feature buffer full.");
 			return -1;
@@ -108,7 +100,16 @@ static int features_dir_cb(DIR *dir, const char *name, struct stat *st,
 			return -1;
 	}
 
-	fst->pos = snprintf_buffer(fst->buffer, fst->pos, fst->size, "}\n");
+	remaining = fst->size - (fst->pos - fst->buffer);
+	len = snprintf(fst->pos, remaining, "}\n");
+	if (len == -1) {
+		errno = EIO;
+		return -1;
+	} else if (len >= remaining) {
+		errno = ENOBUFS;
+		return -1;
+	} else
+		fst->pos += len;
 
 	return 0;
 }
-- 
2.1.0